extensionsService: Fix copying technical details when extension crashes

This was forgotten when porting to GTK 4, leading to the following error
when user tries to copy the error message produced by an extension:

	JS ERROR: TypeError: Gtk.Clipboard is undefined
	_initActions/<@resource:///org/gnome/Shell/Extensions/js/extensionsService.js:255:31
	run@resource:///org/gnome/Shell/Extensions/js/dbusService.js:177:20
	main@resource:///org/gnome/Shell/Extensions/js/main.js:19:13
	run@resource:///org/gnome/gjs/modules/script/package.js:206:19
	start@resource:///org/gnome/gjs/modules/script/package.js:190:8
	@/nix/store/fwnkwvhwm3kqck4fhkc5y5z853radggg-gnome-shell-40.0/share/gnome-shell/.org.gnome.Shell.Extensions-wrapped:7:17
11 jobs for !1795 with wip/jtojnar/ext-clipboard in 2 minutes and 58 seconds (queued for 1 second)
detached
Status Job ID Name Coverage
  Pre Review
passed #1244034
check_commit_log

00:00:17

passed #1244036
check-merge-request

00:00:25

 
  Prep
passed #1244038
build-fedora-container

00:00:33

 
  Review
passed #1244041
eslint

00:00:50

passed #1244042
eslint_mr

00:00:48

passed #1244039
js_check

00:00:24

passed #1244044
no_template_check

00:00:12

passed #1244043
potfile_check

00:00:21

 
  Build
passed #1244045
build

00:01:47

passed #1244046
flatpak
flatpak

00:01:21

 
  Test
passed #1244047
test

00:00:52